St Louis County Policeclaim Brown was shot while running away after he tried to snatch a gun from an officer while in the back of a patrol car.

While reporting on Brown's death, some news organisations chose a picture of Brown wearing a Nike basketball jersey while using his hands to pose with what could be interpreted as a "gang sign".

The controversial photo of Michael Brown used by many news outlets.(Facebook)

While other pictures of Brown eventually appeared in the media, African-Americans used the hashtag #IfTheyGunnedMeDown to suggest what picture of themselves the news would use if they were to be shot by police.

The photos contrasted pictures of young black male describing themselves as looking like "thugs" with photos of them posing at graduations, dressed in army uniforms or with family members while asking the question "#IfTheyGunnedMeDown What picture would they choose?"

The hashtag soon trended worldwide on Twitter, as thousands asked questions about how minorities are represented in the media.

St. Louis County Policespokesman Brian Schellman promised a lengthy investigation into the shooting of Brown.

"We're still trying to piece together what happened and why," he added.